Adaptor for mounting replacement electric motors



March 11, 1969 T n- 3,432,705

ADAPTOR FOR MOUNTING REPLACEMENT ELECTRIC MOTORS Filed Jan. 13. 1967 (PRlOR ART) INV E NTO R. #56 55 [/NDTVf/T W'S.M J

United States Patent 6 Claims ABSTRACT OF THE DISCLOSURE An adaptor plate suitable for connecting an electric motor to an oil burner blower housing so that the motor shaft is correctly and exactly centered within the pilot hole in the blower wheel housing, despite mismatched mounting parts of the motor and/or blower housing, including at least three spaced groups of apertures in the adaptor plate, each group having apertures at different radii with respect to a given center on the adaptor plate, so that at least three projecting members may be mounted in the respective groups of apertures at a suitable radius to engage the lip of said blower wheel housing pilot hole at at least three spaced portions thereof and thereby arrange the adaptor plate center to be congruent with the blower Wheel axis, means for securing the adaptor plate to the blower wheel housing, and means for securing the electric motor ,to the adaptor plate so that the motor shaft is coaxial with the given center on the adaptor plate.

Background of the invention In the usual construction, an oil burner employed for heating purposes includes a blower housing, within which is a blower wheel. An electric motor is mounted flush against the outside of the housing with its shaft centered on a pilot hole in the housing so as to correctly engage means within the housing for driving the blower wheel and a fuel pump located on the other side of the blower wheel housing.

A practical problem arises in the field servicing of fuel burners of this type, in that when the electric motor burns out or otherwise requires replacement or bench servicing, the field serviceman is presented with an annoying dilemma. Either he must carry a very large variety of' electric motors with him on his calls in order to replace the defective motor until it can be service, or he must remove the defective motor without immediately replacing it thereby interrupting the employment of that particularly fuel burner. Neither of these alternatives is satisfactory, and in the oil burner maintenance business, this problem is notorious.

Under present conditions the aforesaid large variety of motors must be carried about with the serviceman if the oil burner is to be kept in service, because the various oil burner manufacturers space their mounting bolts differently, and more importantly because they employ a wide variety of pilot hole diameters. The importance of the diameter of the pilot hole is, as aforesaid, that the pilot hole when correctly aligned with the motor determines the exact position of the motor shaft and thereby assures that the motor shaft will not be eccentrically engaged with the blower wheel, which is necessary for correct operation. Heretofore, the varied pilot hole diameters have made it impossible for a serviceman to carry a single replacement motor or even a small number of different replacement motors for the purpose of keeping the oil burner in service while its own motor is taken back to the shop for repair or replacement.

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Brief summary of the invention An adaptor plate suitable for connecting an electric motor to an oil burner blower housing so that the motor shaft is correctly and exactly centered within the pilot hole in the blower wheel= housing, despite mismatched mounting parts of the motor and/or blower housing, including at least three spaced groups of apertures in the adaptor plate, each group having apertures at dilferent radii with respect to a given center on the adaptor plate, so that at least three projecting members may be mounted in the respective groups of apertures at a suitable radius to engage the lip of said blower wheel housing pilot hole at at least three spaced portions thereof and thereby arrange the adaptor plate center to be congruent with the blower wheel axis, means for securing the adaptor plate to the blower wheel housing, and means for securing the electric motor to the adaptor plate so that the motor shaft is coaxial with the given center on the adaptor plate. The provision of an adaptor plate according to the invention allows a single electric motor, or any one of a small number of different electric motors, carried by the serviceman, to be adapted to any of a variety of blower housings for secure mounting thereto, and for accurate alignment of the motor and the pilot hole so that the motor shaft correctly engages the blower wheel for transmission of power thereto.

Brief description of the figures An illustrative embodiment of the invention is described hereinbelow in a detailed description of the invention with reference to the figures, in which:

FIG. 1 is a perspective view of an oil burner motor adaptor according to the invention shown adapting a motor to an oil burner blower wheel housing;

FIG. 2 is an exploded side elevation view of the apparatus shown in FIG. 1 with the oil burner housing partially broken away to show internal details thereof;

FIG. 3 is a view of the adaptor plate} shown in FIG. 2 taken along plane 3-3 therein;

FIG. 4 is a view of the other major face of the adaptor plate shown in FIG. 2 taken along plane 44 therein; and

FIG. 5 is a section view of the adaptor plate shown in FIGS. 2-4 taken along plane 5-5 in FIG. 4.

Referring now to the figures there is shown in FIG. 1 an oil burner indicated generally at 10, illustrating the usual arrangement of parts, which include a blower wheel housing 11, a fuel pump 13 mounted to one side of blower wheel housing 11, and an electric motor 14 mounted on the opposite side of blower wheel housing 11 from fuel pump 13. For convenience, the designation 14 (employed in FIG. 1) will indicate the motor having the correct mounting parts for direct bolting to housing 11, while the designation 14' (employed in FIG. 2) will indicate any motor having differently spaced or proportioned mounting parts, which may nevertheless be correctly mounted to housing 11 by recourse to the present invention.

As may best be seen in FIG. 2, within housing 11 is carried for rotation a blower wheel 12, which is powered by motor 14 and which in turn powers pump 13. The blower wheel housing 11 includes a pilot hole indicated at 1121 which is generally circular and defined by a peripheral rim 11b. In the normal construction of oil burners, an electric motor such as 14 or 14 is provided with a circular flange 14a concentric with the motor shaft 14b and having a diameter so as to fit closely within pilot hole 11a in contact with the inside lip 11c of peripheral rim 11b, so as to correctly center shaft 14b with relation to blower housing 11 and thereby with relation to blower wheel 12 and fuel pump 13. The correct centering of shaft 14b allows the smooth transmission of power due to the absence of eccentricities or misalignments of the power train from motor 14 to blower wheel 12 and fuel pump 13. An electric motor such as 14 or 14 also includes a diametrically located pair of mounting flanges 14c, 140. through which mounting bolts 15 (FIG. 1) are inserted to secure the motor to the blower housing 11 at tapped apertures in shoulders 1121 thereon.

When the motor 14 has correctly mating parts for the particular blower wheel housing 11 in question, i.e. when the mounting flanges 14c, 14d align correctly with the tapped apertures and shoulders 11d, and more particularly when the circular flange 14a closely fits into the pilot hole 11a, the motor 14 may be mounted directl to the blower housing 11 '(FIG. 1) so that the shaft 14b is correctly engaged with the blower wheel 12 and the fuel pump 13.

The present invention presupposes that this normal, prior art arrangement does not obtain in a given service situation. That is to say, when the correctly matched motor 14 (FIG. 1) is burned out or in need of repair or replacement, the serviceman cannot conveniently have with him a wide variety of necessary replacement motors so that the flanges 14c, 14d and the flange 14a are correctly proportioned to give the necessary critical mating with the blower housing 11. The present invention provides the adaptor plate (FIGS. 2-5) according to the invention so that the motor 14 which does not mate correctly with the blower'housing 11 can still be mounted to the blower housing 11 with the correct critical centering of the shaft 14b within the pilot hole 110.

Adaptor plate 20 is preferably generally circular in outline, with respect to a center C, and includes a diametrically opposed pair of flanges 21, 22 lying along a diameter D, each of which includes an elongated slot 21a, 22a respectively lying along diameter D. Slots 21a, 22a are of appropriate width to accommodate closely the bolts 15 and a length suflicient to allow alignment with a wide variety of diametrical spacings beween such tapped apertures and shoulders 11d. B this means the adaptor plate 20 can itself be secured by bolts 15 to a wide variety of blower housings.

As may best be seen in FIG. 5, adaptor plate 20 includes a central aperture 23 centered on center C so that th motor shaft 14b may protrude therethrough. The adaptor plate 20 includes a first face 25 viewed in FIG. 4 and a second face 26 viewed in FIG. 3 which are respectively matable with the motor 14"and the blower housing 11. Face 25 includes a circular depressed portion 25a centered on center C and adapted to receive the circular flange 14a of motor 14. Face 26 includes a smaller diameter depressed portion 26a, and a plurality of apertures 27 which extend from face 26 through to depressed portion 25a. In the illustrated embodiment four apertures 27 are employed, two located along diameter D and two others located along diameter E which is perpendicular to diameter D. The four apertures 27 are located on the same radius with respect to center C, and each includes a countersunk portion 27a in the face 26, so that flat head screws 30 (FIG. 2) may be inserted from face 26 through the apertures 27 to engage tapped apertures in motor 14. By this means motor 14' is secured to adaptor plate 20, with circular flange 14a thereof nested within depressed portion 25a and with shaft 14b protruding through aperture 23 entered on adaptor plate center C.

As may be best seen in FIG. 3, a plurality of blind apertures appears in face 26 of adaptor plate 20 in the stock surrounding depressed portion 26a. While blind apertures are shown, full apertures may also be employed. These blind apertures are divided into three groups which are located approximately 120 apart with respect to center C. In the illustrated embodiment, a first group 30a-30h is located at a portion of face 26 adjacent diameter E, while a second group a-35h is located approximately 120 therefrom in a first direction, and a second group a-40h is located approximately 120 from the first group in the other direction therefrom. Correspondingly designated apertures among, the groups are located 120 apart, e.g. aperture 30a is 120 from aperture 35a which is 120 from aperture 40a which in turn is 120 from aperture 30a. The various apertures in each group are located on different radii with respect to center C, and correspondingly designated apertures among the groups are located on the same radii with respect to center C. For example in group 30a-30h aperture 30a is located on the smallest radius with respect to center C, aperture 30h is located on the largest radius with respect to center C, and the intermediate designated apertures are located on intermediate radii. Also apertures 30a, 35a, 40a are on the same radius with respect to center C, and apertures 30b, 35b, 40]) are on the same larger radius with respect to center C, etc.

Three projecting members 50 (FIG. 2) which may be short dowels or which may be set-screws, depending upon whether or not the aforesaid blind apertures are tapped or not, are provided so that one projecting member 50 can be inserted into one of the apertures in each of the three groups of apertures. When so inserted, the members 50 project outward of face 26. By this means the necessary alignment between the motor 14 and the blower housing 11 is achieved. Thus a projecting member 50 can be inserted into each of apertures 30a, 35a, 40a or into each of any other group of three apertures having a common radius. When three projecting members 50 are thus insertcd, a circle having the radius in question is determined, and when the radius in question is chosen to be the same as the radius of the lip 11c of the pilot hole 11:: in question, the projecting members 50 will contact the lip 11c at three peripheral points when plate 20 is brought into contact with blower housing 11, thereby centering center C of plate 20 with the center axis of pilot hole 11a. Since the motor 14' is centered on plate 20, the shaft 14b is thereby centered within pilot hole 11a. When the blower housing 11 having a different diameter pilot hole 11a is encountered the projecting members 50 can be shifted to a different set of three blind apertures, e.g. apertures 30a, 35c, 40e, adapted to fit closel within the different pilot hole 11:: in question.

In operation, a standard motor 14' will be secured to face 25 of adapter plate 20 by the four screws 30, and will be kept in the servicemans kit of supplies. When a burned out motor is removed in the field from a blower housing 11, the diameter of the pilot hole will be measured, and the three projecting members 50 will be inserted into three of the apertures 30, 35, 40 providing the closest fit, and the adaptor plate 20 with the standard motor 14' secured thereto will be placed against blower 11 so that the projecting members 50 rest against the lip of pilot hole 11a thereby centering the motor shaft 14b correctly within pilot hole 11a. The bolts 15, which normally secure the motor 14 directly to the housing 11 (FIG. 1), are then inserted through the slots 21a, 22a to secure the adaptor plate 20 to the blower housing 11, thereby securing the standard motor 14 also to the blower housing 11. The bolts 15 will correctly engage the tapped apertures in housing 11, because the slots 21a, 22a provide a wide latitude of bolt 15 spacing.

It is possible that different size standard motors 14' will be carried by the serviceman and connected to the adaptor plate 20 in the field when different power requirements or the like are met. It is also possible to provide each stand ard motor 14 with its own adaptor plate 20 already secured thereto for convenience. In either case, the serviceman is provided with a means for replacing a wide variety of electric motors with only one or a few varieties of standard motors carried by him in his service calls. Most importantly, this advantage of flexibilit does not sacrifice correct operation of the oil burner 10 during this period of substitution, because the shaft 14b is correctly aligned despite the mismatching of the mounting parts between the standard motor 14 and the housing 11 in question. The important problem of the pilot hole 11a variation is overcome by the device according to the invention.

While the invention has been described with reference to a preferred embodiment thereof, it will be understood by those skilled in the art that certain variations in' the form and arrangement of parts may be practiced Without departing from the spirit of the invention. Since the illustrated embodiment is illustrative, not limiting, all such variations are contemplated as being Within the scope of the invention.

What is claimed is:

1. An adaptor for mounting a replacement electric motor to any of a variety of housings, so that the motor shaft is centered on the housing pilot hole despite disparity between the mounting parts, especially disparity between the outer diameter of the motor mounting flange and the inner diameter of the pilot hole lip, comprising:

(a) a plate having first and second major faces, an axis normal to said plate defining a center, and an aperture through said plate surrounding said center and large enough to allow said motor shaft to unimpeded therethrough;

(b) means defining a plurality of apertures in said first plate face, a group of at least three apertures being located at approximately equispaced locations about a first circle concentric with said center and having a first diameter, a group of at least three other apertures being located at approximately equispaced locations about a second circle concentric with said center and having a second diameter greater than said first diameter, said first and second diameters being approximately equal to the pilot hole diameters forming the extreme of the range with which it is desired to mount said motor, and one or more intermediate groups of at least three apertures each, located at approximately equispaced locations about intermediate circles concentric with said center but having diameters intermediate said first and second diameters;

(c) projecting means adapted to be inserted in any three of said apertures on the same diameter circle so as to project outwardly of said first face to fit inside said pilot hole lip when said first plate face is brought into contact with said housing at said pilot hole;

((1) means for mounting said motor to said second plate face so that said motor shaft coincides with said plate axis through said center; and

(e) means for mounting said plate to said housing.

2. An adaptor according to claim 1 wherein said means for mounting said plate to s-aid housing comprises lateral flange portions of said plate, each having a slotted aperture located along a radius with respect to said center, the location along said radius being such, together with the length of said slot, that congruence with mounting apertures on said housing is attained despite variation from housing to housing, whereby the plate may be bolted to the housing by the same parts normally employed to bolt a motor to said housing.

3. An adaptor according to claim 1 wherein said second plate face includes a depressed portion adapted to receive said motor mounting flange.

4. An adaptor according to claim 1 wherein each of said groups of apertures is arranged peripherally on its reprotrude spective circle so as to correspond to each other group, the plurality of such apertures being thereby divided into three peripherally segregated sets, eachset having one aperture for each of said circles, thereby affording ease of selection of three identical diameter apertures for insertion of said projecting members.

5. An adaptor according to claim 1 wherein said plurality of apertures are blind, and said projecting members comprise close-fitting dowels. 6. A mounting device for installing a replacement electric motor to any auxiliary housing, so that the motor shaft is centered on the housing pilot hole despite variation of the pilot hole diameter from housing to housing, as measured at the lip thereof, comprising:

(a) an electric motor having a shaft; y (b) a mounting device having a face through which said shaft protrudes; said device being connected to said motor; 7

(c) means defining a plurality of apertures in said face, a group of at least three apertures being located at approximately equispaced locations about a first circle concentric with said center and having a first diameter, a group of at least three other apertures being located at approximately equispaced locations about a second circle concentric with said center and having a second diameter greater than said first diameter, said first and second diameters being approximately equal to the pilot hole diameters forming the extreme of the range with which it is desired to mount said motor, and one or more intermediate groups of at least three apertures each, located'at approximately equispaced locations about intermediate circles concentric with said center but having diameters intermediate said first and second diameters;

(d) connecting means for connecting the mounting device to an auxiliary housing and adapted to be inserted in any three of said apertures on the same diameter circle so as to project outwardly of said face to fit inside said pilot hole lip when said plate face is brought into contact with said housing at said pilot hole; and

(e) means for mounting said motor to said mounting device.

References Cited UNITED STATES PATENTS 1,822,342 9/1931 Ehrlich 310-91 1,888,476 11/1932 Scott 248-17 2,523,928 9/ 1950 Szekely 248-2 2,683,006 7/ 1954 Nichols 248-2 2,693,380 11/1954 Flanagan 248-2 2,697,570 12/ 1954 Snyder 248-2 3,104,901 9/1963 Potter 248-2 3,270,221 8/1966 Shaffer 310-91 3,270,222 8/ 1966 Shaffer 310-51 3,378,709 4/1968 Rover 31091 J. D, MILLER, Primary Examiner.

. US. Cl. X.R. 248-2, 16; 310-51 

